* refactor: preliminary cleanup of Deno.runTests()
* Change time measurement to use new Date() instead of
performance.now(). Because there is no guarantee that tests are
run with "--allow-hr" using new Date() guarantees higher
precision of 1ms instead of 2ms.
* Support String type filter in "skip" and "only".
* Split "exitOnFail" into "exitOnFail" and "failFast".
Former tells if "runTests()" should exit with code 1 on test
failure, while latter tells if "runTests()" should stop
running tests on first failure.
* Use "defer" to wait for unhandled promise rejection - this bit
is funky and doesn't seem right, but for now it's just a rewrite
from using "setTimeout". Intended to be fixed in later commits.
* Remove global "__DENO_TEST_REGISTRY", don't expose list of
registered tests (to be addressed in follow up commits)
* Remove arbitrary slow test threshold; use uniform coloring
instead
* add "assertOps" test assertion which makes sure test case
is not "leaking" ops - ie. after test finishes there are no
pending async ops
* apply "assertOps" to all tests in "cli/js/"
* fix numerous tests leaking ops
* document problem with edge case in "clearInterval"
and "clearTimeout" implementation where they
may leak async ops
* move "cli/js/worker_test.ts" to "cli/tests/worker_test.ts" and
run as integration test; workers leak ops because of missing
"terminate" implementation
* rewrite test runner in Rust
* migrate "test" and "runTests" functions from std to "Deno" namespace
* use "Deno.test()" to run internal JS unit tests
* remove std downloads for Deno subcommands
* establish basic event loop for workers
* make "self.close()" inside worker
* remove "runWorkerMessageLoop() - instead manually call global function
in Rust when message arrives. This is done in preparation for structured clone
* refactor "WorkerChannel" and use distinct structs for internal
and external channels; "WorkerChannelsInternal" and "WorkerHandle"
* move "State.worker_channels_internal" to "Worker.internal_channels"
* add "WorkerEvent" enum for child->host communication;
currently "Message(Buf)" and "Error(ErrBox)" variants are supported
* add tests for nested workers
* add tests for worker throwing error on startup
For some reason, the unit tests for Deno.remove() were not being imported to
unit_tests.ts and, consequently, not being executed. Thus, I imported them,
refactored some existent ones and wrote new ones for the symlink removal case.
Since the creation of a symlink is not implemented for Windows yet, assertions
that consider this state were added when the tests are executed in this OS.
